The truck is an important element in the design of skateboards, wheeled platforms, roller skates, inline skates and vehicles. The truck not only supports the wheels of the skateboard, platform, inline skates, roller skates or vehicle, it may also provide the user with a significant degree of directional control.
In a typical skateboard truck, directional control is accomplished by providing the truck with four primary components: a truck hanger, a base plate, a kingpin, and bushings. Typically skateboard trucks (FIGS. 1 and 2) have two (2) axle extensions, which protrude laterally from the sides of the truck hanger upon which the skateboard wheels and bearings are mounted. Skateboard trucks are a wide variety of construction and designs beyond the typical truck described herein. Each of these trucks designs tends to exhibit most, if not all, of the characteristics described below. Skateboard trucks are typically mounted to the skateboard deck in a front (or leading) and rear (or trailing) position along the longitudinal or lengthwise axis of the skateboard deck such that, at rest, the truck axle extensions at the leading position are roughly parallel to the truck axle extensions at the trailing position and all truck axle extensions are roughly perpendicular to the longitudinal axis of the skateboard deck when the skateboard is at rest. If this approximately parallel alignment of the trucks and their respective axles are maintained while the skateboard rolls along the ground, the skateboard's path will be relatively straight.
A skateboard truck typically exhibits some dynamic response when the user of the skateboard or wheeled platform leans to one side or the other. Such dynamic response tends to cause the truck hanger and axles to exhibit a component of rotation, in part, around a vertical axis, or an axis oriented perpendicular to the ground surface upon which the skateboard is positioned. The leading hanger and trailing hanger typically (but not necessarily) rotate in opposite directions. Thus, the user can turn, or otherwise control the forward direction of the wheeled platform, by shifting his or her body from one side of the platform to the other. Bushings are located between the truck base plate and truck hanger in the most common truck design. A kingpin connects the hanger, base plate and bushings together. The threaded kingpin can be tightened and loosened to modify rigidity of the bushings, and the dynamic response characteristics of the truck. Loose or slack bushings generally allow greater movement of the hanger about the kingpin and vertical axis of the truck, and thus are less responsive to slight weight shifts than are tight or rigid bushings.
Most, if not all skateboard truck designs exhibit some undesirable ride characteristics. One such undesired ride characteristic is instability or “speed wobble”, which occurs when the axle and hanger develop a resonant frequency of vibration and uncontrolled wobbling within their typical range of motion. This can cause instability in the user's control of the skateboard, wheeled platform or vehicle. Speed wobbles occur on most skateboard truck designs. Different designs experience these wobbles at different speeds and under different conditions.
Most of the common skateboard truck designs do not transfer energy generated by the rider into the rotation of the skateboard wheels, resulting directly in the locomotion of a skateboard, wheeled platform or vehicle. Accordingly, what is needed is an improved truck assembly that can dynamically steer a wheeled platform, substantially reduce the impact of speed wobbles under typical riding conditions, and generate rotational energy to be used to propel the skateboard, wheeled platform, roller skates, inline skates, or vehicle.
Additionally, for maximum transfer of energy from the rider to the rotation of the at least one rotor, axle or wheel, the rider's gravitational, centrifugal and muscular energy should be structurally supported predominantly or entirely by components actively involved in the transfer of energy from the platform to the wheels. Accordingly, what is additionally needed is an entirely new truck design that strives to minimize support structures that are not used directly in the transfer of energy from the rider into the wheels.